<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>html5新增语义化标签</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        header,
        nav,
        article,
        aside,
        footer{
             color: white;
            line-height: 100px;
            text-align: center;
            background-color: lightgreen;
            border:1px solid lightcoral;

        }
        header,
        nav,
        footer{
            width: 800px;
            height: 80px;
            margin: 10px auto;
           
        }
        article{
            position: relative;
            float: left;
            width: 390px;
            height: 180px;
            margin:10px ;
        
        }
        /* article,
        aside{
            text-align: center;
        } */
        article section{
            position: absolute;
            left: 20px;
            bottom: 20px;
            width: 200px;
            height: 120px;
            background-color: lightblue;
            margin: 20px auto;
        }
        aside{
            display: inline-block;
            width: 390px;
            height: 180px;
            margin: 10px;
        }
        
    </style>
</head>
<body>
    <header>头部标签</header>
    <nav>导航栏标签</nav>
    <article>
        内容标签
        <section>定义文档某个区域</section>
    </article>
    <aside>侧边栏标签</aside>
    <footer>尾部标签</footer>
    
</body>
</html>